高压扭转变形对纯W再结晶行为的影响

Effect of High-Pressure Torsion on Recrystallization Behavior of Pure Tungsten

摘要:

在较低温度条件下完成了难熔金属烧结纯W高压扭转实验,通过改变扭转圈数,利用EBSD、XRD、DSC等多种检测与计算方法分析了高压扭转变形纯W在后续加热过程中再结晶组织及行为的变化。结果表明：高压扭转变形后,纯钨组织的形变储存能增大,激活能降低,但变形后组织的再结晶温度仍处于高值。DSC测试后,原始烧结组织发生明显的晶粒长大情况,而由HPT变形产生的细晶钨再结晶组织仍较为细小,平均晶粒尺寸约4-6μm,且随着扭转圈数增大晶粒尺寸未发生明显变化,变形组织的热稳定性较好。

Abstract:

The High-pressure torsion(HPT)deformation of sintered pure tungsten was carried out under low temperature condition. Recrystallization microstructures and behavior of pure W during the subsequent heating was analyzed under different torsion turns, which using a variety of detection and calculation methods such as EBSD, XRD and DSC. The results show that the deformation storage energy of pure W increases and the activation energy decreases after HPT deformation, but the recrystallization temperature is still high. Relative to obvious grain growth of the original sintered structure, recrystallized microstructure produced by HPT deformation is still small after DSC testing. The average grain size is about 4-6 μm. With the tortsion turns increases, grain size did not change significantly and deformed tissue is relatively stable.